2. you need a company to "sponsor" you for your medical so you will do it usually in the CAAC approved medical place near where that company is based.
3. If you only have a CPL (not an ATPL licence) and you train outside of China at a CAAC approved flight school, you and a Chinese airline/company have to pre register with the CAAC BEFORE starting to learn to fly, otherwise you have to convert your licence in China. If you only have a CPL,this would usually involve doing an IR & CPL/MECR flight test, IR, CPL & ATP Written exam and 20 hours training in a high performance aircraft( if you have not done some flying in a bigger aircraft) however if your company is part 135, i'm pretty sure you don't need to do the high performance training
This year a new regulation come in which means you now need a min of 500 hours to convert a foreign licence.
If you have a foreign ATPL, which i'm guessing you do) then the process is different and i think you know it.
4. The Chinese regs for Biz Jets (part 135) are exactly the same as the FAA part 135 regulations, so you can check the FAA regs for minimums etc. Out of interest the Chinese part 121 regs (airline) are also based on FAA part 121 regs, but have a number of differences.
5. As stevieboy said the CAAC process can take a long time. However if your company is part 135 you can get some kind of temp licence based on your foreign licence, that will let you start flying in China. I'm not sure exactly how this works but I know an American captain who is flying an air ambulance in China and he was allowed to fly a Biz jet on a temp licence before passing his Chinese ATPL written exam and therefore didn't have a full Chinese licence. Might be something to look into.